m$ has taken away the ability to choose not to install updates so machines will randomly reboot at night and waste time that could be used crunching

That's only on the Home version. In the Pro version you can still choose not to install updates. Even then, you could simply edit the registry to auto-login to a user account and resume crunching right after reboot.

I have an i5-5300U 4-core (physical) w/ HD 5500 graphics. 24 execution units.
Does anyone know right balance of CPU cores settings to load the GPU to best performance?
How much free CPU does the GPU need?
Right now I'm running 2 WU instances on GPU.
Boinc computing preferences set to "On Multiprocessor systems, use at most 75%".

Boinc Manager Tasks shows "Running (.04 CPUs + 0.5 Intel GPUs)"

Should I use different values in GPU section for avg_ncpus and max_cpus?
Do I also need to add-in a similar section for the AVX app or let BOINC handle it?

I want to ensure the GPU gets enough free CPU, but not quite sure how much to dedicate to it.
Any help is appreciated! :)

Unfortunately today having found out that Media Center is being removed I may have to keep at least one PC on Win 7 as no other program works for my USB TV stick, Just tried some others and they are either complicated to set up or for some reason fail to see all the TV channels, Media Center just works. Oh well.

I will be doing the same as you, I use my secondary PC as a DVR currently.